Obstructive sleep apnea behind drivers falling asleep at the wheel

Nearly a third of people with obstructive sleep apnea (OSA) report falling asleep while driving. A Canadian study investigating OSA, sleepiness and driving found that people with more severe OSA, greater age, and shift workers had the greatest likelihood of falling asleep at the while. But the good news is people using continuous positive airway pressure (CPAP) and higher age (meaning over age 65) were less likely to crash or have near misses. Details were published in the Canadian Journal of Respiratory, Critical Care, and Sleep Medicine. With a growing aging demographic and increasing rates of obesity, OSA is becoming more common. This makes it even more important to identify and treat patients with the condition, according to Dr. Marcus Povitz, a clinical assistant professor of medicine at the University of Calgary. He was a study coauthor. Read: QUIZ: Test your knowledge of obstructive sleep apnea The 2016/17 Canadian Health Measures Survey reported that 30% of Canadians were at high risk for OSA; but that only 6% reported having received a diagnosis. Those numbers are likely higher now. And at least one study showed people with OSA have a 2.4-fold increased risk of vehicle crashes. The 2011 Canadian Thoracis Society (CTS) guidelines state that one out of every five adults has at least mild sleep apnea, and one in 15 had moderate apnea. New guidelines were released in 2017 by the American Academy of Sleep Medicine which are accessible online. At the same time, the medical treatment of OSA is a known area of inequity in Canadian healthcare. There is a widely divergent availability of diagnostic testing and funding for treatment between provinces, the study said The researchers, who were from across Canada, conducted an anonymous online survey in both official languages, which asked about experiences with OSA, including the impact of OSA on driving. It was administered from March 1 to April 30, 2019. Researchers looked for adults 18 years of age or older with a self-reported physician diagnosis of OSA in Canada. A total of 600 people completed the survey. A total of 5% of respondents reported they received a diagnosis of OSA in the last six months; 9% within 6 to 12 months, and the remainder reported a longer time since diagnosis or did not remember. Moderate-severe OSA was reported by 76% of the respondents. Over 90% reported driving. Of these, 72% reported they drove between one and 20 hours driven each week, while 18% reported they drove on a shift work schedule. The study found that 28% of the participants reported they fell asleep while driving at least once, ever, and that 5% reported they experienced a crash or near miss within the last 5 years. Those who reported moderate OSA were more slightly more likely than those with severe cases to have a crash or near miss, and much more likely than those with mild cases, this was not statistically significant, Dr. Povitz said. Those who had shift work were also at increased risk for crashes or near misses. “Shift work increased the odds of a crash,” Dr. Povitz said. People who reported they used CPAP for their OSA and older age had a lower risk of crashes and near misses. Factors such as sex, hours driven and current use of CPAP (not necessarily use of treatment at time of incident) were not significantly associated with the odds of falling asleep while driving. Dr. Povitz noted that issues related to driving are complicated. “Experience might mitigate risk of crash, many older people drive less and some may experience less sleepiness from OSA,” he said in an email. Study limitations included the fact the responses were based on self-reports, and the sample wasn’t big enough to make comparisons across provinces with different reporting rules for drivers. Dr. Povitz coauthored a review on the diagnosis and treatment of OSA In 2017 the CMAJ. That article stated that polysomnography is the gold standard for diagnosis, a test that is conducted in a sleep lab. Treatments include the regular use of CPAP or oral appliances such as mandibular advancement devices, as well as weight loss and moderate exercise for patients who are overweight. “CPAP is the gold standard for treatment however it is not universally tolerated which is when alternatives like a dental appliance or surgery can be considered,” he said. A review of OSA in the journal of Sleep Medicine and Disorders in 2020 highlighted the association between OSA and hypertension and cardiovascular disease (CVD) pointing out it is the most common cause for both diseases. “The main etiological factor of OSA is obesity, which is a rapidly growing global epidemic,” it said. It emphasized the importance of screening for OSA as the major underlying cause of essential, and resistant hypertension, which in turn can lead to CVD and can cause end-organ damage. I It also stressed the importance of encouraging patients to use CPAP regularly because of its proven beneficial effects. Some studies show that higher systolic and diastolic blood pressure are seen during 24-hour ambulatory blood pressure monitoring both in patients with mild and severe OSA than in obese control patients who don’t have OSA – meaning even mild OSA needs treatment. “Treatment with CPAP therapy decreases sympathetic activity, high blood pressure (BP), heart rate, and CVD as well as its associated mortality,” it said. A 2020 review on the diagnosis and management of OSA in JAMA stated that OSA is associated with a two- to three-fold increased risk of cardiovascular and metabolic disease. “In many patients, OSA can be diagnosed with home sleep apnea testing, which has a sensitivity of approximately 80%.” Treatments can include weight loss and exercise, CPAP, oral appliances which help hold the jaw forward during sleep, and surgery of the pharyngeal soft tissues or facial skeleton to enlarge the upper airway. Hypoglossal nerve stimulation may be an option for some patients whose BMI is less than 32, it said.

Obstructive sleep apnea behind drivers falling asleep at the wheel

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